Press



March 9, 1937- A BYERLElN 2,073,238

PRESS Filed April 14, 19 34 2 Sheets-Sheet l MMM 4' krz/ Gttorneg March9, 1937. A. A. BYERLEIN PRESS Filed April 14, 1934 2 Sheets-Sheet 2 |||rLlll Q 3nne ntor (Ittorneg Patented Mar. 9, 1937 PATENT OFFICE Arthur aByerlein,

General Machinery Ohio, a corporation of PRESS Detroit, Mich., assignorto Corporation,

Hamilton, Delaware Application April 14, 1934, Serial No. 720,51

6 Claims. (01. 1 13-38) This invention relates to power presses and moreparticularly to presses for drawing sheet metal or the like.

One object of the invention is the provision of a power press having awork 'plunger or slide which is so driven as to operate at comparativelyspeed during the work forming part of a cycle of operations and atahigher rate of speed during. the major portion of the remainder of thecycle. Another object of the invention is the provision of a press fordrawing or working metal, having a variable speed electric motor drivefor the work Fig. 3 is a diagrammatic showing of the electrical controlsystem; v

Fig. 4 is a partly diagrammatic view, of the controlling switches andtheir operating cams,

- and Fig. 5 is a diagrammatic the timing of the'various speedchanges.

Conventional drawing er minute, but then the total production in anygiven time period will also be reduced. In accordance with the presentinvention, however,

the operating shaft by means of which the movable slide is driven, is sooperated that the speed of the plunger is materially slower during thedrawing part of a cycle of operations in order that a comparatively highnumberof strokes per minute is attained without correspondinglyincrearing the speed of the drawing operation itself.

The press maybe of any suitable character having a movable slide whichcarries a die for drawing the work, and may be equipped with the usualillustration showing serving as blank holding members, forming mem- Asherein shown the press is provided with a plurality of mechanicallyoperated upper 5 slides H and I2 and the mechanically operated 7 lowerslide 42 which are moved in timed relationship as more fully set forthin my prior United States Patents Nos. 1,768,503 and 1,967,464.

Referring more particularly to the drawings I0 10 the shaft 20.

id with the two dwelling it may blank holder together with the lowerportion of themes Such lower die may be operated by means of the lowerthe carrying shde designated generally 42 Slide 42 is guided forvertical movement its opposite ends being connected to operating rods48the 55 upper ends of which are formed as eccentric straps 49 engagedwith cylindrical surfaces 48 eccentrically provided adjacent oppositeends of the operating shaft l3. 5 The motor 2| which serves as a drivingforce for the operating shaft 13 by means of which the various slidesare reciprocated in timed relationship is a two-speed electric motor ofcom-.

paratively high horse power capacity so that the motor can pull thepress through its'peak loads without requiring the storing of energy ina large flywheel. A flywheel of substantial size would prevent rapidlychanging the speed of operation of the press at predetermined points inthe cycle 15 of operations, so it is preferred that no flywheel beemployed. Mounted on the press frame at a suitable location is a camshaft 50, operated by a timing sprocket chain 5| from the operatingshaft l3 so that the shafts 58 and I3 will move in synchronism and atthe same speed of rotation. The cam shaft 50 is provided with a numberof cams 52 to 51 inclusive as shown in Fig. 4 for the operation ofswitches proper times in the sequence of press operations. The electricmotor 2| is provided with a high speed'winding connected to the leads 85of a three-phase power supply and also with a low speed windingconnected through the leads 68. Power switches 81 and 68 respectivelycomplete the connection to the power source 88. It will be understoodthat when the switch 68 is closed, the motor is operated at low speedandwhen the switch 81 is closed and switch 68 opened the motor willoperate at high speed. The high speed of operation is such as to give adesired high speed movement of the press parts for the ineffectiveportions of a cycle of operations, while the low speed of the motor issuitable to provide a drawing speed that will be slow 'enough so 40 thatthere will be a minimum amount of breakage in drawing the metal.

As shown in Fig. 5, the motor is automatically controlled by means ofthe cams 52 to 51, the switches 58 to 83 and the additional apparatusshown in Fig. 3. The press may be started by the operator and theoperating shaft 13 will then be driven at high speed from the point a tothe point cm Fig. 5, point c being about 80degrees from point a. Fromthe po" t c'to the point d, an angle corresponding substantially to thedrawing or effective operations on the metal, the shaft moves at lowspeed. From the point 12 which is about 190 degrees from point a, theshaft moves at high speed until it has rotated a total of about 340degrees up to the point e.

point e to the point I which is about 350' degrees from point a theshaft moves at low speed and at the point I the brake is applied so asto stop the shaft when point a is again reached.

As an example'of the essential parts of the motor controlling means,Fig. 3 illustrates diagrammatically the electrical connections that maybe employed. The power source 89, I as shown, is connected to a smallmotor 88 which drives a low voltage generator ll. The generator Hisupplies current for .the low voltage or controlling system. l2.is amain switch and energizes the'low voltage system. 13 and 16 are twomanually operated switches adaptedto be simultaneously operated by thetwo hands of the attendant to initiate a cycle of operations. When theswitches 18 and 14 are both closed by the attendant, a circuit iscompleted from the generator it through switch '52, across contact '35,through a normally-closed switch 82, through 58 to 63 inclusive atswitch83 which is normally closed and through the coils 16 and 11 of the lowvoltage circuit breakers l8 and 79 respectively. When the circuitbreaker coils are thus energized the circuit breaking elements completetheir respective circuits, the breaker 19 being provided in a resetcircuit 80 and the breaker 18 being arranged to connect one side of thelow voltage source to'a lead 8|. With both switches 13 and I4 closedcurrent may flow from the lead- 8| across the closed contacts 83 andacross the closed contacts '84 to a winding 85, this winding having anarmature which closes the switch 81 of the motor 2i and holds the switch'81 closed as long as the winding 85 is energized. A suitable overloadcircuit breaker 88 may be employed in series with the winding 85.

When the attendant closes the. switches 13 and 14 the motor 2| is thusconnected so as to operate at high speed. The operator holds theswitches 13 and Id closed until the crank shaft has moved some distance,up to the point I) of Fig. 5 for example, at which point the switch 58is closed by cam 52. When the switch 58 closes a holding circuit throughthe lead 81 is completed maintaining the coil 85' energized andpermitting the operator to remove his hands from the two switches 13 and15. The closed connection across the switch 58 maintains the motor inoperation at high speed until the point e is reached after about 80degrees total travel of the operating shaft l3. At this point the switch58 is automatically opened by its controlling cam, and switch 60 isclosed by cam 54. The switch 60 connects the lead 81 to a winding 80having an armature which closes the switch 68 of the motor 2! and whichholds the switch 88 closed as long as the winding 98 is energized. Theswitch 58 being opened has deenergized the winding 85 and thus openedthe switch 61. The motor will therefore operate at its low speed ofmovement throughout the drawing part of the cycle of operations, up tothe point d about degrees displacement from the initial point a. At thepoint (1, the switch 68 is automatically opened to deenergize thewinding 88 and thus open the switch 88 and at the same time the switch59 is automatically closed so as to again energize the winding 85 andcause the motor to operate at high speed. The motor continues moving athigh speed from the point d to the point e which is about 340 degreesfrom point a. At the point e the switch 59 is opened automatically andswitch 6| is closed so that the speed of the motor is changed from highspeed hack to low speed. The motor moves at low speed for about 10degrees movement of the shaft l3, up to the point Land at, the point ithe.

switch 58 opens and switch 82 closes. When the switch 62 closes both ofthe switches 81 and 88 of the motor 25 are open, and a stopping force isapplied to the shaft i8 through a suitable brake by means of an armaturecontrolled by a winding 9! which is in series with switch 82. Thecircuit is completed through the winding 9! through switch 82 and acrossthe contacts. 83 which are now closed inasmuch as the operator haspreviously released his hand from the switch 13 and permitted the returnmovement of the switch to its position shown in Fig. 3. The press willthus stop automatically after a complete cycle of operations the shafti3 having moved through a total of 360 degrees and again returned to itsstarting position a.

At the same time switch 82 closes for the app ication of the brake, theswitch 63 also opened 15 through another cycle.

automatically by the cam 51, switch 63 remaining open, however, onlyinstantaneously, this switch without requiring a complete cycle ofoperations 20 before stopping.

It will now be apparent that when the operator so desires, he can startthe press in operation,

tion, the drawing slide is moved comparatively work is thus avoided.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that th ment of theslide.

6. and

